Screw propeller



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(Mndell) C. MYERS.

SCREW 'PROPELLE'R. No. 467,322. Patented Jan. 19, 1892-.

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'(ModeL O MYERS SCREW PEOPELLER.

Patented Jan. 19, 1892.

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No, 467,322. Patented Jan. 19,, 1892.

INVENTDR UNITED STATES PATENT UFFIC E.

CHARLES MYERS, OF MANCHESTER, EN GLAND,ASSIGNOR OF THREE-FOURTI-IS TO MATTHEW ELLS, OF SAME PLACE.

S'CREW-PROPELLER.

SPECIFICATION forming part of Letters Patent No. 467,322, dated January 19, 1892.

Application filed October 13, 1890. Serial No. 368,033. (Modeh) Patented in England September 4, 1888, No. 12.730, and in France June 25, 1889,110. 199,187.

To all whom it may concern:

Be it known that 1, CHARLES MYERS, designer, a subject of the Queen of England, residing at Manchester, in the county of Lancaster, have invented certain new and useful Improvements in Screw-Propellers, (for which I have obtained Letters Patent inEngland, No. 12,730, dated September 4, 1888, and in France, No. 199,187, dated June 25,1889,) of which the following is a specification.

The object of this invention is to construct a screw-propeller for'steamships from which an increased thrust or propelling force may be obtained with a reduction of slip and in r 5 the vacuum formed at the rear of the propeller. Screw-propellers for steamships are at present usually formed with two or more blades standing out radially from a central boss situated on the axis of rotation of the propeller, each of such blades having a single shank and being twisted to form a portion of the thread or threads of a screw.

This invention consists, essentially, in constructing the propeller with a series of blades,

(two or 1nore,) each in the form of a severed loop, both ends of which are attached to the boss and helically disposed relatively to the axis of the central opening and angularly arranged relatively to the axis of the boss of the 0 propeller and to the propeller-shaft. It will be fully described with reference to the accompanying drawings, in which a propeller constructed in accordance with this'invention is shown as designed for different purposes,

5 like letters of reference referring to similar parts in each.

Figure 1 is an elevation of a propeller designed for large-size steam ships Fig. 2, a plan of Fig. 1; Fig. 3, sectional elevations of same,

40 drawn to an enlarged scale; Fig. 4, an expanded view of one blade, Fig. 5, a similar view of single blade with base for connecting it to the boss; Fig. 6, an elevation of small propeller designed for torpedoes or the like, and

Fig. 7 an elevation of two-bladed propeller.

The screws may be constructed of any pit-ch, according to the nature of the work they are destined to perform, and the blades may be made solid with the boss, or removable, as

shown in Fig. 5, in the same way as with the ordinary propeller-blades at present. Each blade A of the propeller is constructed in the form of a loop, both ends of which are attached to the boss B, one in advance of the other, thus having two radial arms a and b, connected together by a flat segmental piece 0 at their extremities. The radial arm a is placed in advance of the arm 17 on the boss B, and both are placed at an angle-to the axis of the boss and the propeller-shaft, the position being such that in relation to the central opening Got the loop that is formed they are helically disposed toward its radial axis.

In the propeller shown in Fig. 6 it will be seen that each complete blade is equal to two of the ordinary radial blades, with the propellingsurface increased by the addition of the segmental part c.

It is found that a propeller constructed as herein described has more thrust and grip on the water by reason of its increased surface and of allowing the dead-water near the boss to pass through the opening 0 in a direct line with the axis, whereby the vacuum at the back of the propeller is reduced to a minimum; also, that the blades, on account of their looped form and of each arm of which the blade is composed being attached to the boss one in advance of the other, are very much stronger and less liable to fracture than are the ordinary blades attached at one end and free at the other.

Having now fully described the invention, what I desire to claim and to protect by Letters Patent is- 1. A screw propeller having blades, each in the form of a severed loop, provided at the tip with a flat'vertical surface which extends beyond the opening in the blade and at the center with two arms, one placed in advance of 0 the other upon the boss and helically disposed relatively to the axis of the central opening and angularly arranged relatively to the longitudinal axis of the boss to which the two arms areseparately attached.

2. A screw-propeller having blades provided at the center with two arms set angularly on the boss, one in advance of the other, which decrease in pitch toward the periphery, provided with a fiat vertical segmental. con- I provided at their outer end with a flat vertical segmental connecting-piece c, which forms a flat screw-blade with a central opening 0, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 3d day of October, 1890.

CHARLES MYERS.

Witnesses:

I. OWDEN OBRIEN, CHAS. OVENDALE. 

